Module 4 Intro
1. Module 4 Intro
1.28. Module Glossary
Module 4—Mechanisms of Population Change
Module Glossary
adaptation: a beneficial variation that helps an organism survive
allopatric: speciation that occurs from a geographical barrier
analogous structures: body parts in different species that have similar functions but evolved separately
barrier: anything that prevents organisms from reproducing
biogeography: the study of the past and present geographical distribution of species
biological barrier: a factor such as behaviour that keeps species reproductively isolated even when they exist in the same region
divergence: the development of one or more new species from a parent species as a result of mutation and adaptation to changing environmental conditions: the parent species continues to exist
embryology: the study of similar features in embryos and evolutionary relationships that may exist
fossils: the remains of past life found in sedimentary rock
geographical barrier: geological formations that keep organisms separated
gradualism: the theory that evolution occurs slowly and steadily in a linear fashion
gradualism: gradual change occurs in a steady, linear way over time
homologous structures: body parts in different species that have the same evolutionary origins and structural elements but may have different functions
hypothesis: a statement that provides one possible answer to a question or one possible explanation for an observation
inheritance of acquired characteristics: a theory that characteristics acquired during an organism’s lifetime could be passed to its offspring
mutagen: something that causes an increased rate of mutation
mutation: a change in the genetic material of an organism (DNA)
natural selection: the process that results when the characteristics of a population of organisms change because individuals with certain inherited traits survive specific local environmental conditions and, through reproduction, pass on their traits to their offspring
paleontology: the study of ancient life through the examination of fossils
punctuated equilibrium: evolutionary history is said to consist of long periods of equilibrium, interrupted by periods of speciation
punctuated equilibrium: the theory that suggests that evolutionary history consists of long periods of stasis (stable equilibrium), punctuated by periods of divergence
selective advantage: an organism’s variations increase its chances of surviving
selective disadvantage: an organism’s variations reduce its chances of surviving
selective pressure: environmental conditions that select for certain characteristics of individuals and select against other characteristics
sexual selection: a type of natural selection where characteristics are selected based on mate preferences
speciation: the formation of new species
strata: a layer of rock or soil that has a consistent character and is different from layers above and below it
transformation: the evolution of one species into another as a result of mutation and adaptation to changing environmental conditions, resulting in the replacement of the old species
transitional fossil: the remains or impression of a prehistoric organism that shows intermediary links between groups of organisms and shares characteristics common to these groups
variation: visible or invisible differences between individuals
viable offspring: offspring that are healthy and able to reproduce and create new offspring